Ideas, for most of the Early Modern Philosophers, are the direct objects of thought. So, how it is that they come to be found in the mind is if significance for understanding the nature of thought. The Empiricists held that since one may only think thoughts about ideas that are acquired from the senses, that all ideas must have been furnished by the senses. For instance, those who are blind are known to be unable to think about color, not possessing the ability to acquire color ideas through sight.
Thomas Hobbes
(5 April 1588 – 4 December 1679)
"Concerning the thoughts of man....the origin of them all is that which we call SENSE." So begins Hobbes' infamous work Leviathan. By sense, Hobbes seems to mean the physical sensory processes, like vision or touch, initiated by external objects.
"The cause of sense is the external body, or object, which presses the organ proper to each sense, either immediately, as in taste and touch, or mediately, as in seeing, hearing, and smelling; this pressure, by the mediation of nerves and other strings and membranes of the body, continued inwards to the brain and heart, causes there a resistance, or counter-pressure, or endeavor of the heart, to deliver itself; this endeavor, because outward, seems to be some matter without.
From these basic sensory thoughts, more complex thoughts avail themselves through the imagination, "nothing but a decaying sense" or a less vivacious sensory idea that we are less apt to attach an "outwardness" to. As these ideas develop in complexity by memory and repetition, a "train of thought" develops, some of which is constrained by a certain design, such as inference, and others unconstrained and purely creative. To Hobbes, the object itself causes the sense perception and acts as a directing mechanism,sending the need for perception and understanding to the appropriate sense. So we do not hear a sound or see a color; rather, the color in wanting to be seen calls upon the appropriate sense of sight to be perceived. He distinguishes taste and touch as being immediate senses and sight, hearing and smell as mediate senses.
Hobbes' epistemology centers on reason, which he defines as the sum of parts of knowledge--both in construction (addition) and destruction (subtration). "These operations are not incident to numbers only, but to all manner of things that can be added together and taken one out of another." (chapter 5) The more knowledge we have, the more we can add to or whittle from the larger body to get at actual truth. Hobbes is careful to note that part of this method requires a distinguisher between man and animal, eventually determining that man will always include consequence and effect in his reasoning: "The use and and of reason is not the finding of the sum and truth of one, or a few consequences...but to begin at these, and then proceed from one consequence to another."
John Locke
(29 August 1632 – 28 October 1704)
Purpose:
"...to inquire into the origin, certainty, and extent of human knowledge, together with the grounds and degrees of belief, opinion, and assent - I shall not at present meddle with the physical consideration of the mind, or trouble myself to examine in what its essence consists, or by what motions of our spirits or alterations of our bodies we come to have any sensation by our organs, or any ideas in our understandings, and whether those ideas do in their formation, any or all of them, depend on matter or not." (CHU I.1.2) Locke is attempting to account for differing opinions and beliefs from one person to another.
Locke acknowledges that the sum of man's knowledge is far smaller than what man would desire it to be, but is quick to argue that we only need to know of what will be of use to us.
"...though the comprehension of our vast understandings comes exceedingly short of the vast extent of things, yet we shall have cause enough to magnify the bountiful author of our being for that proportion and degree of knowledge he has bestowed on us, so far above all the rest of the inhabitants of this our mansion...We shall not have much reason to complain of the narrowness of our minds, if we will only employ them about what may be of use to us; for of that they are very capable." (CHU I.1.5)
Like Hobbes, Locke argued that all ideas are gained by a sensory process, of "outer" and "inner" senses or what he referred to as "sensation" and "reflection". "All ideas come from Sensation and Reflection". (II.i.1) As support for this claim, Locke asks his readers to introspect on their own thoughts, and "examine his own thoughts and thoroughly search his understanding--and then let hem tell me whether all the original ideas he has there are any other than of the objects of his senses, or of the operations of his mind..." (II.i.5) There are numerous other arguments, both in support of empiricism and against rationalism, that Locke offers in support of his view.
Arguments against Nativism
"There is nothing more commonly taken for granted than that there are certain principles...which must necessarily be the constant impressions which the souls of men receive in their first beings." Arguments against nativism attempt to resolve Malebranche's theses concerning seeing all things through God. Locke claims that this argument is problematic for several reasons. One problem is that there is no such reality as universal assent, and a second claims that "children and idiots"--who have souls and minds--are yet unable to take notice of notions. "Thus truths may be imprinted on the mind which it never did, nor shall ever know; for a man may live long, and die at last in ignorance of many truths which his mind was capable of knowing, and that with certainty." (CHU I.2.5)
Arguments for Empiricism
Molineaux's Problem
Locke exchanged letters with Mr. Molineaux, who presented this problem to Locke:
"Suppose a man born blind and now adult, and taught by his touch to distinguish between a cube and a sphere of the same metal and nearly of the same bigness, so as to tell, when he felt one and the other, which is a cube, which the sphere. Suppose then the cube and sphere were placed on a table and the blind man be made to see. Quaere, whether by his sight, before he touched them, he could now distinguish and tell which is the globe, which the cube?" (II.ix.8)
Locke and Molineaux agree that the answer is NO.
"For though he has obtained the experience of how a globe, how a cube affects his touch, yet he has not yet obtained the experience that what affects his touch so or so must affect his sight so or so." (II.ix.8)
Without touching the globe and the cube, the man now able to see would not be able to tell the difference between the two objects. He does not have a history of sight and judgement on that sight in order to do otherwise.
Immanuel Kant
22 April 1724 – 12 February 1804)
Thought not traditionally considered an "Empiricist", recently scholars are sifting our various ways in which he advocated this position with respect to the acquisition of concepts. For instance, Kant states that "...by means of sensibility objects are given to us, and it alone supplies us with intuition...[and] all thought must, in us, refer ultimately to sensibility, because no object can be given to us in any other manner than through sensibility." (CPR A19/B33) The definition of sensibility, he says, is our ability to acquire ideas as objects affect our minds, and the effect of the object on us is sensation. Furthermore, the thing we perceive that corresponds to our sensation is what he calls matter.
Thomas Hobbes
(5 April 1588 – 4 December 1679)
"Concerning the thoughts of man....the origin of them all is that which we call SENSE." So begins Hobbes' infamous work Leviathan. By sense, Hobbes seems to mean the physical sensory processes, like vision or touch, initiated by external objects.
"The cause of sense is the external body, or object, which presses the organ proper to each sense, either immediately, as in taste and touch, or mediately, as in seeing, hearing, and smelling; this pressure, by the mediation of nerves and other strings and membranes of the body, continued inwards to the brain and heart, causes there a resistance, or counter-pressure, or endeavor of the heart, to deliver itself; this endeavor, because outward, seems to be some matter without.
From these basic sensory thoughts, more complex thoughts avail themselves through the imagination, "nothing but a decaying sense" or a less vivacious sensory idea that we are less apt to attach an "outwardness" to. As these ideas develop in complexity by memory and repetition, a "train of thought" develops, some of which is constrained by a certain design, such as inference, and others unconstrained and purely creative. To Hobbes, the object itself causes the sense perception and acts as a directing mechanism,sending the need for perception and understanding to the appropriate sense. So we do not hear a sound or see a color; rather, the color in wanting to be seen calls upon the appropriate sense of sight to be perceived. He distinguishes taste and touch as being immediate senses and sight, hearing and smell as mediate senses.
Hobbes' epistemology centers on reason, which he defines as the sum of parts of knowledge--both in construction (addition) and destruction (subtration). "These operations are not incident to numbers only, but to all manner of things that can be added together and taken one out of another." (chapter 5) The more knowledge we have, the more we can add to or whittle from the larger body to get at actual truth. Hobbes is careful to note that part of this method requires a distinguisher between man and animal, eventually determining that man will always include consequence and effect in his reasoning: "The use and and of reason is not the finding of the sum and truth of one, or a few consequences...but to begin at these, and then proceed from one consequence to another."
John Locke
(29 August 1632 – 28 October 1704)
Purpose:
"...to inquire into the origin, certainty, and extent of human knowledge, together with the grounds and degrees of belief, opinion, and assent - I shall not at present meddle with the physical consideration of the mind, or trouble myself to examine in what its essence consists, or by what motions of our spirits or alterations of our bodies we come to have any sensation by our organs, or any ideas in our understandings, and whether those ideas do in their formation, any or all of them, depend on matter or not." (CHU I.1.2) Locke is attempting to account for differing opinions and beliefs from one person to another.
Locke acknowledges that the sum of man's knowledge is far smaller than what man would desire it to be, but is quick to argue that we only need to know of what will be of use to us.
"...though the comprehension of our vast understandings comes exceedingly short of the vast extent of things, yet we shall have cause enough to magnify the bountiful author of our being for that proportion and degree of knowledge he has bestowed on us, so far above all the rest of the inhabitants of this our mansion...We shall not have much reason to complain of the narrowness of our minds, if we will only employ them about what may be of use to us; for of that they are very capable." (CHU I.1.5)
Like Hobbes, Locke argued that all ideas are gained by a sensory process, of "outer" and "inner" senses or what he referred to as "sensation" and "reflection". "All ideas come from Sensation and Reflection". (II.i.1) As support for this claim, Locke asks his readers to introspect on their own thoughts, and "examine his own thoughts and thoroughly search his understanding--and then let hem tell me whether all the original ideas he has there are any other than of the objects of his senses, or of the operations of his mind..." (II.i.5) There are numerous other arguments, both in support of empiricism and against rationalism, that Locke offers in support of his view.
Arguments against Nativism
"There is nothing more commonly taken for granted than that there are certain principles...which must necessarily be the constant impressions which the souls of men receive in their first beings." Arguments against nativism attempt to resolve Malebranche's theses concerning seeing all things through God. Locke claims that this argument is problematic for several reasons. One problem is that there is no such reality as universal assent, and a second claims that "children and idiots"--who have souls and minds--are yet unable to take notice of notions. "Thus truths may be imprinted on the mind which it never did, nor shall ever know; for a man may live long, and die at last in ignorance of many truths which his mind was capable of knowing, and that with certainty." (CHU I.2.5)
Arguments for Empiricism
Molineaux's Problem
Locke exchanged letters with Mr. Molineaux, who presented this problem to Locke:
"Suppose a man born blind and now adult, and taught by his touch to distinguish between a cube and a sphere of the same metal and nearly of the same bigness, so as to tell, when he felt one and the other, which is a cube, which the sphere. Suppose then the cube and sphere were placed on a table and the blind man be made to see. Quaere, whether by his sight, before he touched them, he could now distinguish and tell which is the globe, which the cube?" (II.ix.8)
Locke and Molineaux agree that the answer is NO.
"For though he has obtained the experience of how a globe, how a cube affects his touch, yet he has not yet obtained the experience that what affects his touch so or so must affect his sight so or so." (II.ix.8)
Without touching the globe and the cube, the man now able to see would not be able to tell the difference between the two objects. He does not have a history of sight and judgement on that sight in order to do otherwise.
Immanuel Kant
22 April 1724 – 12 February 1804)
Thought not traditionally considered an "Empiricist", recently scholars are sifting our various ways in which he advocated this position with respect to the acquisition of concepts. For instance, Kant states that "...by means of sensibility objects are given to us, and it alone supplies us with intuition...[and] all thought must, in us, refer ultimately to sensibility, because no object can be given to us in any other manner than through sensibility." (CPR A19/B33) The definition of sensibility, he says, is our ability to acquire ideas as objects affect our minds, and the effect of the object on us is sensation. Furthermore, the thing we perceive that corresponds to our sensation is what he calls matter.
Kant also responded to external world skepticism.